Radio loud-speaker



Dec. 17, 1929. P. P. SCHROEDER 1,739,615

RVADIO LOUD SPEAKER Filed Aug. 29. 1927 hog In 0271 tor By QM 05m Patented Dec. 17, 1929 UNITED STATES PATENT QFFICE PAUL SCHROEDEB, F GREENWICH, CONNECTICUT, ASSIGNOR 0F ONE-TENTH TO WILLIAM C. STRONG, OF GREENWIOH, CONNECTICUT RADIO LOUD-SPEAKER Application filed August 29, 1927. Serial No. 216,191.

My invention relates to improvements in loud speakers, and the same relates more particularly to a loud speaker wherein a parchment or other flexible sheet material diaphragm is employed as the ultimate sound producing agent.

My invention involves certain improvements over my pending application filed May 31st, 1927, Serial No. 195,318. In th1s pending application, one electromagnetic unit serves to operate both the low and high tone diaphragms, whereas in the present application separate units are employed with an improved arrangement of vibrating wires for vibrating the separate high and low tone diaphragms.

An object is to provide a novel loud speaker wherein the high and low tone pitches of sound are conveyed to independent diaphragms for reproduction.

Another object resides in the novel and effective manner in which the magnetic units are mounted. to produce the best results.

Still another object has been to provide a speaker which is unusually clear of tone, and

at the same time capable of being manufactured at a very low cost.

Other objects and advantages will become apparent as the invention is better understood from the specification to follow.

In the drawings Figure 1 is a longitudinal section taken through approximately the center of my improved speaker.

Fig. 2 is a side elevation of same, illustrating one of the low tone and side diaphragm panels.

Fig. 3 is a perspective of the irregular pyramidally shaped high pitch diaphragm. and

Fig. 4 is a bottom view of the base of my loud speaker showing the same in elevation.

Referring now to the drawings for a more detailed description, like numerals designate like parts of my invention A rectangular base frame 1 is provided with a platform 2 having suitable openings therein, is secured to the frame at a substantial distance from the bottom edge thereof, to allow sufficient space to accommodate the bulkiness of a pair of electro-magnetic units 3 and 4 respectively, which are of conventional type.

The numeral 3 designates the low pitch unit, while 4 is the high pitch unit. A low pitch diaphragm 5 constructed of leather, or some other strip material particularly adapted for transmitting low tone vibrations, is adapted to be arranged upon the base frame in spaced parallelism to the platform 2, and is formed with a pair of openings directly over the respective magnetic units.

Arranged over the opening and over the magnetic unit 8 is a disk 6 in direct vibratory connection with the underlying unit. The box-like body of the speaker includes a frame 7, and a suitable dome and frame 8 superimposed thereon. Directly under the dome 8 is a low tone diaphragm 9 clearly illustrated in Fig. 1, having its outer edge secured to the top section of the frame 7. Other low tone diaphragms 10 complete the side walls of the box-like body. These side walls or panels, as well as the diaphragm 9 are constructed preferably of a starched linen, or similar material which will reproduce the low tone pitches with the necessary perfection.

Inwardly of the two endpanels of my speaker, are located a pair of high pitch diaphragms 11 and 12 respectively. These high pitch diaphragms'are of an irregular pyramidal formation, having their apex portions shaped to form an oblique section 13. These high pitch diaphragms are further formed with openings 14. These high pitch diaphragms are preferably constructed of a very fine sheet metal, however, I do not wish to limit myself to an particular material, but desire to employ t at material which is the most effective in reproducing the desired tone.

Connected to the disk 6 on the low pitch diaphragm 5 are a plurality of wires A directed to the low 'tone diaphragm, which includes the upper diaphragm, and the side wall diaphragm or panels. In passing to the end panels, the wires extends through the openings 14 formed in the high pitch diaphragms 11 and 12 respectively.

' In addition to the majority of the low tone wires passing through .their respective diaphragms, I desire that one or more of these wires pass through the top of the high pitch diaphragm as clearly shown in Fig. 1, of the drawing.

The electro-magnetic unit 4 which controls the high pitch diaphragms 11 and 12. respectively, is of conventional type and includes the usual coil and diaphragms which are not shown in the drawings. To the usual diaphragm within this unit, is attached a wire 15, which at its free end has connected a. plurality of wires B. A pair or more of these wires are connected to the individual oblique sections of the high tone diaphragms 11 and 12 respectively.

One or more of these wires B are attached to the top of one of the high. pitch diaphragms, as well as having another wire connected to the top low tone diaphragm 9.

In operation, the electro-magnetic units 3 and 4 being in the same circuit together, may function simultaneously. Taking the units individually; the vibrating disk 6 which causes the diaphragm 5 to operate, also vibrating the low tone diaphragms 10, besides assisting in vibrating the high tone diaphra 'm 12. The unit 4 is rimarily employed to vibrate th pair of hig tone diaphragms, but this unit alsoassists in operating the low tone diaphragm 9.

This will be clearly shown in the drawings, and the novelty of employing a pair of electro-magnetic coils in the osition shown, as wires will have a direct vi ratory movement with respect to the various diaphragms. In other words, each wire affords a direct improvement in respect to the diaphragm with which it is connected.

I The switch 16 may be used for cutting in or out, one or the other of the units, or else employing both at the same time. It may be deslrable to use either one or the other of the diaphragms in reproducing the different pitch sounds.

Having thus described my invention, what I claim as new is 1. In a sound reproducing device of the character described, a box like frame, diahragms of a certain resonant value arranged m said-frame to provide side walls therefor, diaphragms of a different resonant value arranged within said frame and actuating means for vibrating said diaphragms.

2. In a sound reproducing device of the character described, a plurality of diaphragms arranged in box like formation, inwardly converging diaphragms of a distinct resonant value arranged within the area surrounded by the aforementioned diaphra ms, and independent actuating means for t e respective groups of diaphragms.

3. In a sound reproducing device of the character described comprising a plurality of diaphragms arranged in box-like formation, a second group of diaphragms within the area surrounded by the diaphragms ar-v ranged in box-like formation arranged in angular relation with respect to each other and with respect to the diaphragms disposed in box-like formation, the first mentioned diaphragms being of a distinct resonant value from those of the second mentioned group, and independent actuating means for vibrating the diaphragms of both groups.

4. In a sound reproducing device of the character described, diaphragms arranged in box like formation, diaphragms arranged within the area surrounded by the said first mentioned diaphragms of a different resonant value, and means for vibrating said diaphragms.

5. In a sound reproducing device of the character described, diaphragms arranged in box like formation, pocketed diaphragms of distinct resonant value from the first mentioned diaphrag1ns,said pocketed diaphragms having their open sides adjacent the inner sides of certain of the first mentioned diaphragms, and actuating means for vibrating both groups of diaphragms.

6. In asound reproducing device of the character described, diaphragms arranged in box like formation, pyramidal shaped diaphragms of distinct resonant value with respect to the first mentioned diaphragms, said last mentioned diaphragms being open at their base side, said ocketed dia hragms being arranged with t eir open sid ias adja cent the inner sides of certain of the first mentioned diaphragms,actuating means, and flexible strands connecting the said diaphragms to the said actuating means for the transmission of vibration from the actuating means to the respective diaphragms.

In testimony whereof I affix my signature.

PAUL P. SCHROEDER. 

